build.rs

// Copyright (c) 1997-2025 Eric S. Raymond
// Copyright (c) 2026 Google LLC
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

use std::env;
use std::path::PathBuf;

fn main() {
    let out_dir = PathBuf::from(env::var("OUT_DIR").unwrap());

    // The header lives at the crate root, next to Cargo.toml.
    let manifest_dir = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap());
    let header = manifest_dir.join("gif_lib.h");

    println!("cargo:rerun-if-changed={}", header.display());

    let bindings = bindgen::Builder::default()
        .header(header.to_str().unwrap())
        .allowlist_recursively(true)
        .generate_comments(true)
        .default_macro_constant_type(bindgen::MacroTypeVariation::Signed)
        .rustified_enum("GifRecordType")
        // Only generate types and vars (no functions).
        .ignore_functions()
        .generate()
        .expect("Unable to generate bindings for gif_lib.h");

    bindings.write_to_file(out_dir.join("c_types_gen.rs")).expect("Couldn't write c_types_gen.rs");
}